(Solved): Help with parts d and e The graph shows the displacement from equilibrium of a mass-spring system a ...

The graph shows the displacement from equilibrium of a mass-spring system as a function of time after the vertically hanging system was set in motion at time $t=0$. Assume that the units of time are seconds, and the units of displacement are centimeters. The first $t$-intercept is $(0.75,0)$ and the first maximum has coordinates $(1.25,2)$. (a) What is the period $T$ of the periodic motion? $T=$ seconds (b) What is the frequency $f$ in Hertz? What is the angular frequency $\omega$ in radians / second? $f=$ Hertz $\omega =$ radians / second (d) Determine the amplitude $A$ and the phase angle $\gamma$ (in radians), and express the displacement in the form $y(t)=A\cos (\omega t-\gamma )$, with $y$ in meters. $y(t)=$ meters (e) With what initial displacement $y(0)$ and initial velocity $y^{\prime }(0)$ was the system set into motion? $\begin{array}{ll}y(0)=& \text{ meters }\\ y^{\prime }(0)=& \text{ meters / second }\end{array}$